CN102074752B - Heating circuit of battery - Google Patents

Abstract

The invention provides a heating circuit for a battery, the heating circuit includes a switch device (10), a switch control module (100), a unidirectional semiconductor element D10, a damping element R, and a transformer (T), the switch control module ( 100) electrically connected to the switching device (10); the battery, the damping element R, the first coil of the transformer (T), and the switching device (10) are connected in series to form a battery discharge circuit; and the battery, The damping element R, the second coil of the transformer (T), and the unidirectional semiconductor element D10 are connected in series to form a battery charging circuit. The present invention utilizes the transformer (T) to realize current limiting and energy storage, which can not only reduce the current in the charging and discharging circuit, avoid damage to the battery, but also reduce the energy consumption of the whole heating process.

Description

battery heating circuit

technical field

The invention belongs to the field of power electronics, in particular to a heating circuit for a battery. the

Background technique

Considering that cars need to drive under complex road conditions and environmental conditions, or some electronic devices need to be used in poor environmental conditions, batteries used as power sources for electric vehicles or electronic devices need to adapt to these complex conditions. In addition to considering these conditions, the service life of the battery and the charge-discharge cycle performance of the battery also need to be considered, especially when the electric vehicle or electronic equipment is in a low-temperature environment, the battery needs to have excellent low-temperature charge-discharge performance and high input. output power performance. the

Generally speaking, under low temperature conditions, the impedance of the battery will increase, and the polarization will increase, thereby resulting in a decrease in the capacity of the battery. the

In order to maintain the capacity of the battery under low temperature conditions and improve the charging and discharging performance of the battery, the invention provides a heating circuit for the battery. the

Contents of the invention

The purpose of the present invention is to provide a heating circuit for a battery to solve the problem that the impedance of the battery will increase and the polarization will increase under low temperature conditions, which will lead to a decrease in the capacity of the battery. the

The heating circuit for a battery provided by the present invention includes a switch device, a switch control module, a unidirectional semiconductor element, a damping element, and a transformer, and the switch control module is electrically connected to the switch device; the battery, the damping element, and the transformer The first coil of the transformer and the switching device are connected in series to form a battery discharge circuit; and the battery, the damping element, the second coil of the transformer and the unidirectional semiconductor element are connected in series to form a battery charging circuit. the

When the battery needs to be heated, the switch control module can be used to control the switch device to be turned on, and to be turned off when the current in the battery discharge circuit reaches a preset value, and then the transformer will recharge the stored electric energy to the battery . During this process, the damping element heats up due to the current flowing through it, thereby heating the battery. The transformer can play the role of current limiting, and the preset value can be set according to the battery's own properties, therefore, the current in the battery charging and discharging circuit is controllable, avoiding excessive current and causing damage to the battery. In addition, the controllability of the magnitude of the current can also provide corresponding protection for the switching device, preventing it from being burned due to excessive heat generation. the

In addition, the transformer of the present invention is an energy storage element and has a current limiting function, which can fully recharge the energy stored by itself to the battery through the battery charging circuit, reducing energy loss during heating. the

Other features and advantages of the present invention will be described in detail in the following detailed description. the

Description of drawings

The accompanying drawings are used to provide a further understanding of the present invention, and constitute a part of the description, together with the following specific embodiments, are used to explain the present invention, but do not constitute a limitation to the present invention. In the attached picture:

Fig. 1 is the circuit diagram of the heating circuit provided by the present invention;

Fig. 2 is the waveform timing diagram of the heating circuit provided by the present invention;

Fig. 3 is the circuit diagram of the heating circuit according to the first embodiment of the present invention;

Fig. 4 is the circuit diagram of the heating circuit according to the second embodiment of the present invention;

Fig. 5 is the circuit diagram of the heating circuit according to the third embodiment of the present invention;

Fig. 6 is the circuit diagram of an embodiment of the switching device in the heating circuit provided by the present invention; And

Fig. 7 is a circuit diagram of another embodiment of the switching device in the heating circuit provided by the present invention. the

Detailed ways

Specific embodiments of the present invention will be described in detail below in conjunction with the accompanying drawings. It should be understood that the specific embodiments described here are only used to illustrate and explain the present invention, and are not intended to limit the present invention. the

It should be pointed out that, unless otherwise specified, when mentioned below, the term "switch control module" refers to any control command (such as a pulse waveform) that can output control commands (such as pulse waveforms) according to set conditions or set moments to control the corresponding switching devices connected to it. The on-off controller, for example, can be a PLC; when mentioned below, the term "switch" refers to a switch that can realize on-off control through electrical signals or realize on-off control according to the characteristics of the components themselves, either It is a unidirectional switch, such as a unidirectional switch composed of a bidirectional switch and a diode in series, or a bidirectional switch, such as a metal oxide semiconductor field effect transistor (Metal Oxide Semiconductor Field Effect Transistor, MOSFET) or with an antiparallel The IGBT of the freewheeling diode; when mentioned below, the term "bidirectional switch" refers to a bidirectional switch that can realize on-off control through electrical signals or realize on-off control according to the characteristics of the component itself, such as MOSFET or belt IGBT with reverse and freewheeling diodes; when mentioned below, a unidirectional semiconductor element refers to a semiconductor element with a one-way conduction function, such as a diode; when mentioned below, the term "charge storage element" refers to any charge that can realize The storage device, such as a capacitor, etc.; when mentioned below, the term "current storage element" refers to any device that can store current, such as an inductor; when mentioned below, the term "forward" refers to energy from The direction in which the battery flows to the energy storage circuit, the term "reverse" refers to the direction in which energy flows from the energy storage circuit to the battery; when referred to below, the term "battery" includes primary batteries (such as dry batteries, alkaline batteries, etc.) and secondary batteries Batteries (such as lithium-ion batteries, nickel-cadmium batteries, nickel-metal hydride batteries or lead-acid batteries, etc.); when referred to below, the term "damping element" refers to any device that achieves energy dissipation by obstructing the flow of current, such as When mentioned below, the term "main circuit" refers to the circuit composed of battery, damping element, switching device and energy storage circuit in series. the

It should also be noted here that, considering the different characteristics of different types of batteries, in the present invention, "battery" may refer to an inductance that does not include internal parasitic resistance and parasitic inductance, or the resistance value of internal parasitic resistance and parasitic inductance An ideal battery with a small value can also refer to a battery pack containing internal parasitic resistance and parasitic inductance; therefore, those skilled in the art should understand that when a "battery" does not contain internal parasitic resistance and parasitic inductance, or When the resistance value of the resistor and the parasitic inductance are small, the damping element R refers to the damping element outside the battery; when the "battery" is a battery pack containing internal parasitic resistance and parasitic inductance, the damping element R is both It can refer to the damping element outside the battery, or it can refer to the parasitic resistance inside the battery pack. the

In order to ensure the service life of the battery, the battery can be heated at low temperature. When the heating condition is reached, the control heating circuit starts to work to heat the battery. When the heating stop condition is reached, the control heating circuit stops working. the

In the actual application of the battery, as the environment changes, the heating conditions and heating stop conditions of the battery can be set according to the actual environmental conditions to ensure the charging and discharging performance of the battery. the

Fig. 1 is a circuit diagram of a heating circuit provided by the present invention. As shown in Figure 1, the present invention provides a battery heating circuit, the heating circuit includes a switch device 10, a switch control module 100, a unidirectional semiconductor element D10, a damping element R, and a transformer T, the switch control module 100 Electrically connected with the switching device 10; the battery E, the damping element R, the first coil of the transformer T, and the switching device 10 are connected in series to form a battery discharge circuit; and the battery E, the damping element R, the transformer T The second coil and the unidirectional semiconductor element D10 are connected in series to form a battery charging circuit. the

Wherein, the switch control module 100 can control the switch device 10 to turn off when the current flowing through the battery E reaches a preset value in the positive half cycle, and control the switch device 10 to turn off when the current flowing through the battery E reaches a preset value in the negative half cycle. When the period reaches zero, the switching device 10 is controlled to be turned on. By continuously passing current through the damping element R, the damping element R generates heat, thereby heating the battery E. the

Fig. 2 is a waveform timing diagram of the heating circuit provided by the present invention. The specific working process of the heating circuit provided by the present invention will be described below with reference to FIG. 2 . Firstly, the switch control module 100 controls the switch device 10 to be turned on. At this time, the positive and negative poles of the battery E are turned on, and the current I in the battery E rises slowly _{mainly due to} the existence of the inductance of the transformer T (please refer to the time period t1), and Part of the energy is stored in the transformer T. When the current I in the battery E reaches a _preset value, the switch control module 100 controls the switch device 10 to turn off, at this time, the transformer T recharges the stored energy to the battery through the unidirectional semiconductor element D10, such as time t2 paragraph shown. Afterwards, when the current in the battery E is zero, the switch control module 100 controls the switch device 10 to turn on again, and starts a cycle again. Repeat this cycle until the battery E is completely heated.

During the above working process of the heating circuit, due to the existence of the inductance of the transformer T, the current I in the battery E is limited. In _addition , the switch control module 100 can also be used to control the timing of turning off the switching device 10 to control the battery E. The current I within _{the main} magnitude. In addition, by changing the turns ratio between the first coil (ie, primary coil) and the second coil (ie, secondary coil) of the transformer T, the magnitude of the charging and discharging current to the battery E can be controlled, for example , the larger the turns ratio between the first coil and the second coil, the smaller the current recharged from the second coil to the battery E.

When the switch device 10 is switched from the on state to the off state, the first coil of the transformer T will induce a large voltage, and when this voltage is superimposed on the switch device 10 together with the voltage of the battery E, Damage to the switching device 10 may result. Preferably, as shown in FIG. 3 , the heating circuit may further include a first voltage absorbing circuit 210, which is connected in parallel to both ends of the first coil of the transformer T, and is used for switching the switching device When the switching device 10 is turned off, the voltage induced by the first coil is consumed to prevent the voltage from damaging the switching device 10 . The first voltage absorbing circuit 210 may include a unidirectional semiconductor element D1, a charge storage element C1, and a damping element R1, the unidirectional semiconductor element D1 is connected in series with the charge storage element C1, and the damping element R1 is connected in parallel to the across charge storage element C1. In this way, when the switch device 10 is switched from the on state to the off state, the voltage induced by the first coil of the transformer T will force the unidirectional semiconductor element D1 to conduct, and the electric energy will continue to flow through the charge storage element C1, and in the It is then consumed by the damping element R1, thereby absorbing the voltage induced by the first coil of the transformer T, and preventing it from damaging the switching device 10 below it. the

Preferably, as shown in FIG. 4, the heating circuit may also include a second voltage absorbing circuit 220 located at both ends of the switching device 10, which is also used to consume the voltage induced by the first coil of the transformer T, so as to avoid this The voltage damages the switching device 10 . The second voltage absorbing circuit 220 includes a unidirectional semiconductor element D2, a charge storage element C2, and a damping element R2, the unidirectional semiconductor element D2 is connected in series with the charge storage element C2, and the damping element R2 is connected in parallel to the unidirectional To both ends of the semiconductor element D2. In this way, when the switch device 10 is switched from the on state to the off state, the voltage induced by the first coil of the transformer T will force the unidirectional semiconductor element D2 to conduct, and the electric energy will continue to flow through the charge storage element C2, and in the Afterwards, when the switch device 10 is turned on, the damping element R2 consumes it, thereby absorbing the voltage induced by the first coil of the transformer T, and preventing it from damaging the switch device 11 . the

The first voltage absorbing circuit 210 and the second voltage absorbing circuit 210 can be included in the heating circuit of the present invention at the same time, as shown in FIG. . Of course, the structures of the first voltage absorbing circuit 210 and the second voltage absorbing circuit 210 are not limited to the above circuit structures, and any suitable absorbing circuit can be applied here. the

In addition, it should be noted that the above "preset value" should be set according to the current that the battery E and other components/components in the heating circuit can withstand. E cause damage, but also consider the size, weight and cost of the heating circuit. the

Fig. 6 is a circuit diagram of an embodiment of the switching device in the heating circuit provided by the present invention. As shown in FIG. 6, the switch device 10 may include a switch K11 and a unidirectional semiconductor element D11 connected in antiparallel to the switch K11, and the switch control module 100 is electrically connected to the switch K11 for controlling the conduction of the switch K11 Turn on and off to control the forward branch of the switch device 10 to turn on and off. the

Fig. 7 is a circuit diagram of another embodiment of the switching device in the heating circuit provided by the present invention. As shown in FIG. 7 , the switch device 10 may also include a switch K12 and a unidirectional semiconductor element D12 connected in series, and the switch control module 100 is electrically connected to the switch K12 for controlling the turn-on and turn-off of the switch K12. to control the switch device 10 to be turned on and off. the

The heating circuit provided by the present invention has the following advantages:

(1) The current limiting function of the transformer T can limit the current in the battery charging and discharging circuit, so as to avoid damage to the battery and switchgear by a large current;

(2) The control of the turn-off timing of the switch device 10 can also control the current size in the battery charging and discharging circuit, so as to avoid damage to the battery and the switch device by a large current; and

(3) The transformer T is an energy storage element, which can store the energy in the battery discharge process, and then charge it back to the battery, reducing the energy loss in the battery heating process. the

Although the present invention has been disclosed through the above-mentioned embodiments, the above-mentioned embodiments are not intended to limit the present invention, and any person skilled in the technical field to which the present invention belongs should be able to make various changes without departing from the spirit and scope of the present invention with modification. Therefore, the protection scope of the present invention should be determined by the scope defined in the appended claims. the

Claims (10)

1. A heating circuit for a battery, characterized in that the heating circuit comprises a switch device (10), a switch control module (100), a unidirectional semiconductor element D10, a damping element R, and a transformer (T), The switch control module (100) is electrically connected to the switch device (10); The battery, the damping element R, the first coil of the transformer (T), and the switching device (10) are connected in series to form a battery discharge circuit; and The battery, the damping element R, the second coil of the transformer (T), and the unidirectional semiconductor element D10 are connected in series to form a battery charging circuit, It is characterized in that, the heating circuit also includes a first voltage absorbing circuit (210), the first voltage absorbing circuit (210) is connected in parallel with both ends of the first coil of the transformer (T), and is used for switching devices ( 10) When it is turned off, the voltage induced by the first coil is consumed. 2. The heating circuit according to claim 1, wherein the damping element R is a parasitic resistance inside the battery. 3. The heating circuit according to claim 1, characterized in that, the first voltage absorbing circuit (210) comprises a unidirectional semiconductor element D1, a charge storage element C1, and a damping element R1, and the unidirectional semiconductor element D1 It is connected in series with the charge storage element C1, and the damping element R1 is connected in parallel with both ends of the charge storage element C1. 4. The heating circuit according to claim 3, wherein the charge storage element C1 is a capacitor, and the damping element R1 is a resistor. 5. The heating circuit according to claim 1, characterized in that, the heating circuit further comprises a second voltage absorbing circuit (220), and the second voltage absorbing circuit (220) is connected in parallel to both ends of the switching device (10) , used for consuming the voltage induced by the first coil when the switching device (10) is turned off. 6. The heating circuit according to claim 5, characterized in that, the second voltage absorbing circuit (220) comprises a unidirectional semiconductor element D2, a charge storage element C2, and a damping element R2, and the unidirectional semiconductor element D2 It is connected in series with the charge storage element C2, and the damping element R2 is connected in parallel with both ends of the unidirectional semiconductor element D2. 7. The heating circuit according to claim 6, wherein the charge storage element C2 is a capacitor, and the damping element R2 is a resistor. 8. The heating circuit according to claim 1, characterized in that, the switch device (10) comprises a switch K11 and a unidirectional semiconductor element D11 connected in antiparallel with the switch K11, and the switch control module (100) is connected with The switch K11 is electrically connected, and is used to control the forward branch of the switch device (10) to be turned on and off by controlling the switch K11 to be turned on and off. 9. The heating circuit according to claim 1, characterized in that, the switch device (10) comprises a switch K12 and a unidirectional semiconductor element D12 connected in series, the switch control module (100) is electrically connected to the switch K12, It is used to control the switch device (10) to be turned on and off by controlling the switch K12 to be turned on and off. 10. The heating circuit according to claim 1, characterized in that the switch control module (100) controls the switch device (10) when the current flowing through the battery reaches a preset value in the positive half cycle turn off, and control the switch device (10) to turn on when the current flowing through the battery reaches zero in the negative half cycle.

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